HR: 09:50h
AN: SA11B-08    [Abstracts]
TI: Investigations Based on the 3D Distribution of Optical Emissions at High Latitudes Obtained by ALIS
AU: * Sandahl, I
EM: ingrid.sandahl@irf.se
AF: Swedish Institute of Space Physics, PO Box 812, Kiruna, SE 981 28, Sweden
AU: Brändström, U
EM: urban@irf.se
AF: Swedish Institute of Space Physics, PO Box 812, Kiruna, SE 981 28, Sweden
AU: Sergienko, T
EM: tima@irf.se
AF: Swedish Institute of Space Physics, PO Box 812, Kiruna, SE 981 28, Sweden
AU: Gustavsson, B
EM: bjorn.gustavsson@phys.uit.no
AF: Department of Physics, University of Troms\o, 9837 Troms\o, Troms\o, NO-9037, Norway
AU: Aso, T
EM: t-aso@nipr.ac.jp
AF: National Institute of Polar Research, 9-10, Kaga 1-chome,Itabashi-ku, Tokyo, 173-8515, Japan
AB: In this paper recent results from ALIS, the Auroral Large Imaging System, are presented. ALIS is a powerful system in Northern Scandinavia capable of doing 3D tomographic spectroradiometry. At present ALIS consists of six stations, spaced about 50 km. Each station has a CCD imager with a six-position filter wheel equipped with narrow-band interference filters. The field-of-view is roughly half all-sky. A positioning system enables imaging from several sites with overlapping fields-of-view for any desired part of the sky. To study the electrodynamics of an auroral arc ALIS images were used for tomographic reconstruction of the 3D distribution of the volume emission rate of aurora, and from that the initial differential particle flux was deduced. This particle flux was used as input into an auroral ionosphere model and ionospheric conductivities were calculated. Imaging of black aurora made it possible to draw conclusions about the causing mechanisms. In an experiment involving the EISCAT Heating facility the formation of an auroral arc was stimulated, leading to conclusions about the importance of a feedback mechanism.
DE: 0310 Airglow and aurora
DE: 2403 Active experiments
DE: 2407 Auroral ionosphere (2704)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2494 Instruments and techniques
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting